Electromagnetic oscillating pendulum



April 7, 1964 REIJIRO n'o ELECTROMAGNETIC OSCILLATING PENDULUM Filed Feb. 27, 1961 United States Patent 3,128,398 ELECTROMAGNETIC OSQHLLATING PENDULUM Reijiro Ito, 7 Komagomehorai-cho, Bnnkyo-ku, Tokyo-to, Japan Fiied Feb. 27, 1961, Ser. No. 92,046 2 Claims. (Cl. 31tl32) The present invention relates to an improvement of a driving mechanism for causing pendulum motion.

The object of this invention is to provide a new and improved driving mechanism suitable for imparting pendulum motion to any object for advertising, amusement or decorative purpose over a long period of time, for example, half year or more, by means of a single dry cell.

Briefly stated, this invention is practiced by providing a pendulum member, a disc shaped or flat permanent magnet secured to the lower end of said pendulum member, a fixed electromagnet disposed to face said permanent magnet with a small air gap therebetween when said magnet passes its lowest position, that is, when the pendulum member assumes the vertical position, a horizontal V-shaped bearing, a knife edge provided on the lower side of an arm secured to said pendulum member at or near its upper end, an electric contact secured to said arm and a curved contact spring cooperating said electric contact, said contact and spring being arranged such that they will engage within a range of small angle around said vertical position so as to energize said electromagnet to produce a magnetic pole of the'same polarity as said permanent magnet.

The features of the invention which are believed to be novel are set forth with particularity in the appended claim. The invention itself, however, as to its organization together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing, in which:

FIG. 1 is a perspective view of one embodiment of this invention;

FIG. 2 is a back view of a lower portion of the driving mechanism;

FIG. 3 is an enlarged perspective view of the electric contacts; and

FIG. 4 is a cross-sectional view illustrating a modified magnet.

Referring now to the accompanying drawing, numeral 1 indicates a base made of Celluloid or other suitable plastic material having an integral upright arm 2. This arm has an opening 4' for hanging it on a wall, a window 4 and a pair of forwardly projecting spaced lugs 5. Secured to said pair of lugs there is a metal plate 6 having a V-shaped bearing 6' at its central upper portion. A pendulum member 7 is made of Celluloid or other plastic material having a rearwardly projecting arm 11 at its upper portion and a permanent magnet 13 at its lower end, said magnet being cemented with its N or S pole facing downward. A spring piece 3 is supported, by means of a V-shaped hook piece 3 having two lugs, in the inner side of the upper portion of the window 4 of the upright arm 2, said hook piece being hooked, at both its lugs, respectively, on the V-shaped bearing 24 formed on the upper inside of said arm 2 and the V-shaped bearing 23 formed on the upper edge of a plate 22 which is affixed to the arm 2. On the lower side of said rearwardly projecting arm 11, there is a knife edge 12' cooperating with said V-shaped bearing 6', and on the outer end of said projecting arm 11, there is secured a metal plate 12 forming an electrical contact 12" adapted to engage with said hook piece 3'. By supporting the knife edge 12 in the V-shaped bearing 6' the pendulum member 7 is suspended free to oscillate to left and right. It will be understood that ac- 'ice cording to said construction, the contact 12" will engage with the hook piece 3 only during oscillating motions of the pendulum member 7 within a range of small angle around its lowest position. The length of the pendulum member 7 is selected such that a small gap is left between the lower face of the permanent magent 13 and the upper face of the base 1. The members 12, 12' and 12" are made of a one piece plate. The spring piece 3 and the hook piece 3' are each made of a metal piece.

As best shown in FIG. 2, in the upper portion of the base 1 an electromagnet 15 comprising a coil 16 wound upon an insulating bobbin 15" fitted on an iron core 15' is supported by a yoke 17 in a position to face with the permanent magnet 13. In the lower chamber of the base 1, there is disposed a dry cell 15 clamped between contact springs 14 and 14 secured to the inner wall of the base 1. The contact spring 14 is connected to the metal plate 6 through an electric wire 19 whereas the other contact spring 14' is connected to one end of the coil 16 through an electric wire 18, the other end of which being connected to the hook piece 3' or the spring piece 3 through a conductor 10. The pendulum member 7 is provided with a set of adjustable screws 9 and 10 adapted to adjust the period of the pendulum.

It should be understood that the coil 16 of the electromagnet 15 is so polarized that its upper face has the same polarity as that of the lower face of the permanent magnet 13.

The operation of the driving mechanism embodying this invention is as follows: If the pendulum member 7 which has been biased to either direction is released, it will swing toward the center line and pass across it towards the opposite direction owing to its inertia although the electromagnet 15 is energized to present the same polarity as the permanent magnet 13 before its comes to the position just above the electromagnet. Then the electromagnet imparts a repulsion force to the permanent magnet 13 to accelerate it. At the extreme end of this opposite direction the pendulum member will begin to reverse its direction of movement. During the first portion of the return movement, the pendulum member 7 will not be disturbed by the electromagnet 15 because it is in the deenergized state. When the pendulum member 7 has sufficiently accelerated in the return direction, however, the electromagnet 15 will be energized by the engagement of the contact 12" and the hook piece 3' so that the pendulum member will pass through the center line while being damped by the repulsion force between the electromagnet and the permanent magnet and thereafter will be accelerated toward the initial position by said repulsion force. When the pendulum member reaches the extreme end of this return movement it will again reverse its direction of movement, thus repeating cycles of pendulum motion.

Accordingly, by suitably attaching a toy or any other design to the pendulum member 7, it is possible to cause said toy or design to oscillate over a very long period of time to be utilized as a toy of an advertising device.

FIG. 4 illustrates a modified form of the electromagnet 15 having a E-shaped magnetic core 15' and a coil 16 wound around the center leg of the core, said electromagnet being disposed opposite to a permanent magnet 13 attached to the lower end of the pendulum member 7. It should be understood that the coil 16 of the electromagnet is so polarized that the center leg'of the core 15' and the permanent magnet 13 will have the same polarity when they face with each other. In this regard, the permanent magnet 13 may be so magentized that its outer legs will have the same polarity as that of the outer legs of the core 15'.

Prior driving mechanism while, heretofore, has been used for imparting pendulum motion to toys and the like over a long period of time comprises an arcuate permanent magnet which is secured to the pendulum member and adapted to pass through an air-core coil of an electromagnet. With such construction, however, as the air gap between the electromagnet and the permanent magnet is large, the efiiciency of the driving mechanism is low. Moreover, such arrangement has such disadvantages that the arcuate permanent magnet has a tendency to collide against the air-core coil, the construction of the supporting arm for the long permanent magnet is complicated and further dismounting of the pendulum member is difiicult.

However, since according to this invention, a disc shaped permanent magnet is secured to the lower end of a depending pendulum member so as to face with an electromagnet just above thereof, the air gap can be decreased extremely resulting in the improvement of the efliciency, avoidance of the collision between the permanent magnet and the electromagnet as well as simplification of the supporting structure for the permanent magnet. Moreover, since the pendulum member is supported by a special knife edge and a cooperating V-shaped hearing, it is easy to dismount it and transport.

As the driving mechanism for attaining the same function as the driving mechanism of this invention, there has also been known a mechanism wherein the polarity of an electromagnet is periodically changed. However, this mechanism is also disadvantageous in that it requires a complicated change-over switch, large power consumption for operating the switch and that the contacts of the changeover switch become spoiled.

However, the driving mechanism constructed in accordance with this invention is operated by interrupted current flow of instant duration as that all defects of the prior mechanisms can be substantially eliminated. More particularly, as the electrical contacts of this mechanism make wiping engagement, they are maintained always clean with small contact resistance.

While the invention has been explained by describing a particular embodiment thereof, it will be apparent that various improvements and modifications may be made without departing from the scope of the invention as defined in the appended claims.

What I claim is:

1. In an electromagnetic oscillating pendulum including an elongated upright frame, a vertical pendulum arm, a small permanent magnet mounted on said arm under the lower end thereof with a pole facing downwardly an electromagnet mounted in said frame beneath said pole of the permanent magnet with the magnetic axis aligned with 1 said pole when said pendulum arm is in the vertical position, and an electric circuit for energizing the electromagnet from a direct current source so that the upper pole of the electromagnet has the same polarity as said pole of the permanent magnet, the improvement therein comprising:

a pair of forwardly projecting spaced lugs towards the uppermost central portion of said frame, a metal plate disposed parallel to said frame having a V-shaped bearing at its central upper portion secured to the ends of said lugs, and, a pair of downwardly projecting front and rear V-shaped lugs disposed over and between said forwardly projecting lugs;

a rearwardly projecting arm on said pendulum arm having a knife edge on the lower side thereof cooperating with said V-shaped bearing for the free oscillation of said pendulum arm;

a V-shaped firstcontact held between said downwardly projecting lugs including spring means biasing said first contact downwards;

a knife edge second contact on said rearwardly projecting arm for engaging said first contact, said first and second contacts being so disposed that they will only engage during oscillating motions of the pendulum arm within a range of a small angle around its lowest position; and,

leads from said contacts closing said electric circuit upon contact,

whereby the electromagnet will not act on the penduarm until the pendulum arm is just about to pass over the electromagnet and its swing will carry it over the electromagnet at which time the electromagnet will impart a strong repulsion force on the permanent magnet to acce1erate it towards the end of its run.

2. A device as claimed in claim 1, said electromagnet having an E-shaped core with coil windings around the center leg of said core.

References Cited in the tile of this patent UNITED STATES PATENTS Dunay Jan. 22, 

1. IN AN ELECTROMAGNETIC OSCILLATING PENDULUM INCLUDING AN ELONGATED UPRIGHT FRAME, A VERTICAL PENDULUM ARM, A SMALL PERMANENT MAGNET MOUNTED ON SAID ARM UNDER THE LOWER END THEREOF WITH A POLE FACING DOWNWARDLY AN ELECTROMAGNET MOUNTED IN SAID FRAME BENEATH SAID POLE OF THE PERMANENT MAGNET WITH THE MAGNETIC AXIS ALIGNED WITH SAID POLE WHEN SAID PENDULUM ARM IS IN THE VERTICAL POSITION, AND AN ELECTRIC CIRCUIT FOR ENERGIZING THE ELECTROMAGNET FROM A DIRECT CURRENT SOURCE SO THAT THE UPPER POLE OF THE ELECTROMAGNET HAS THE SAME POLARITY AS SAID POLE OF THE PERMANENT MAGNET, THE IMPROVEMENT THEREIN COMPRISING: A PAIR OF FORWARDLY PROJECTING SPACED LUGS TOWARDS THE UPPERMOST CENTRAL PORTION OF SAID FRAME, A METAL PLATE DISPOSED PARALLEL TO SAID FRAME HAVING A V-SHAPED BEARING AT ITS CENTRAL UPPER PORTION SECURED TO THE ENDS OF SAID LUGS, AND, A PAIR OF DOWNWARDLY PROJECTING FRONT AND REAR V-SHAPED LUGS DISPOSED OVER AND BETWEEN SAID FORWARDLY PROJECTING LUGS; A REARWARDLY PROJECTING ARM ON SAID PENDULUM ARM HAVING A KNIFE EDGE ON THE LOWER SIDE THEREOF COOPERATING WITH SAID V-SHAPED BEARING FOR THE FREE OSCILLATION OF SAID PENDULUM ARM; 